Recently a friend, Pat Beebe, asked me why we no longer hear the calling of the whip-poor wills. If you can remember back to when your car had a six-volt battery, the dimmer switch was on the floor and a clutch pedal was needed to change gears, you probably remember hearing the calling of a whip-poor-will.

The whip-poor-will’s scientific name is caprimulgidae, which is better known as the nightjar family. Caprimulgidae comes from two Latin words: caper, meaning goat and mulgeo, meaning to milk or suck. Perhaps you have heard the legend that members of this family sucked milk from goats during the night. The species name vociferous is also Latin and means either clamorous or noisy, which is in reference to the loud and distinctive calls of the bird.

Of course, the bird’s common name of whip-poor-will comes from the male’s repeated calling. They are not songbirds.

There are 67 species in the family worldwide, with seven species found in North America. The whip-poor-wills are somewhat owl-like, and their nearest relatives could indeed be owls. However unlike the owls, which are predators, whip-poor-wills are mostly insect-eaters.

Whip-poor-wills were less common before the cutting of the virgin forests. By the late 1800s, the forests were being cleared and the population was growing and spreading over the state. By 1983-84, the population had reached an all-time low in Pennsylvania. Since that time the population has begun to recover, but most of this recovery has been in the south-central part of the state.

Although the reason for the decline is not clear, many believe that the maturing Pennsylvania forests were unable to provide an adequate food supply of insects due to the use of pesticides.

The species is one of the most difficult to confirm nesting because of their nocturnal and secretive habits. Calling ceases after the end of the breeding season and their migration pattern is not well known.

By late April, the whip-poor-wills return to Pennsylvania from their wintering grounds in the southern United States and Mexico. The males will begin immediately calling to attract females. The calls are mostly from dusk until about 9:30 p.m. and then again from 2 a.m. until dawn. They call approximately 50-100 times a minute, with this calling often done for over an hour.

The female does not build a nest but lays her two white eggs with blotches of gray directly on the ground. Although incubation is done mostly by the female, a male can occasionally be seen sitting on the nest. The incubation period is 19-20 days, and after hatching, the young can fly in 20 days. The breeding season of the whip-poor-will appears to coincide with the lunar cycle.

The males sing longer on moonlit nights, therefore hatching of the young occurs when the moon is waxing, giving the adults an easier time to forage food for the young.

Unlike most birds, which perch crosswise on branches, the whip-poor-wills perch lengthwise on branches. They also spend a good deal of time on the ground. From these waiting places, the birds fly up to feed on moths, mosquitoes, gnats and other insects.

This sit-and-wait method of hunting doesn’t use much energy, which allows the birds to arrive earlier in the spring than its close cousin, the nighthawks.

The whip-poor-will has soft feathering, which gives the bird almost silent flight, much like that of the owl. This silent flight aids the bird in catching moths. Many moths have tympanic membranes that pick-up sound, allowing them to escape when a predator is heard approaching.

Most of the time the whip-poor-wills are only heard; however, at night, the birds can sometimes be seen when sitting along dirt roads. The glare of automobile lights causes their eyes to appear red. This red glow is caused by a reflective layer at the back of the retina called the tapetum, which amplifies a small amount of light by passing it back through the retina a second time.

Many legends about the whip-poor-will were handed down by our Native American tribes. One legend told was that an unmarried woman should listen closely for the call of the bird. One call meant that she wouldn’t marry for at least a year, two calls meant impending matrimony, and if the bird called three times or more, it meant she was destined to be a spinster.

Since the bird’s call sounds somewhat like a question, the Omaha Tribe believed that if a person answered no and the bird stopped calling immediately, the person answering would die. If the bird continued calling, the person answering would live a long time.

The Hopi Tribe’s name for the whip-poor-will was “sleeping one” because during the day the bird’s eyes are more of a slit, while at night, they are wide and round.

The Iroquois believed that the little wildflowers known as lady’s slippers were the whip-poor-will’s shoes.

The last whip-poor-will that I heard calling was in the spring of 1968 while a student at the game commission’s training school near Brockway. A male sat on a limb outside our open bedroom window, and his calls were a perfect sound to hear before falling asleep, especially for a group of men on their way to becoming wildlife officers.

Bill Bower is a retired Pennsylvania Game Commission Wildlife Officer. Read his blog and listen to his podcasts on the outdoors at www.onemaningreen.com.